AVSystem Commons Library

A set of common code used in AVSystem for projects written in C.

Currently the included components are:

• Data structures
  • avs_buffer - simple data buffer with circular-like semantics
  • avs_list - lightweight, generic and type-safe implementation of a singly linked list, with API optimized for ad-hoc usage
  • avs_rbtree - basic implementation of a red-black binary search tree
  • avs_vector - generic implementation of a C++-style vector (dynamic array)
• Networking framework
  • avs_http - minimal implementation of a Hypertext Transfer Protocol (HTTP) client
  • avs_net - abstraction layer for TCP, UDP, SSL/TLS and DTLS network sockets, as well as DNS resolution and URL parsing
  • NOTE: avs_commons versions up to 4.0.x included an avs_coap module. This has been removed in favor of the new CoAP implementation distributed as part of Anjay
• Other modules
  • avs_algorithm - currently contains a base64 encoder and decoder
  • avs_log - simple logging framework
  • avs_stream - generic framework for I/O streams; includes pre-implemented streams that can be used through its unified API:
    • md5.h - calculating MD5 hashes
    • netbuf.h - buffered network I/O
    • stream_file.h - file I/O
    • stream_inbuf.h - read-only wrapper for raw memory buffers
    • stream_membuf.h - in-memory stream optimized for a single-message write-then-read cycle
    • stream_outbuf.h - write-only wrapper for raw memory buffers
  • avs_unit - simple and easy to use unit testing framework
  • avs_utils - currently contains utility function for handling time values, psudorandom number generation and string tokenization

Most of the library is written in standard and portable C99. There are some dependencies on POSIX APIs, but there are provisions for replacing them when necessary (see the compat directory for details).

avs_unit relies on some GCC-isms and is unlikely to work with any compiler that is not based on either GCC or Clang.

The code is available under Apache 2.0 License.

Building

Building using CMake

The preferred way of building avs_commons is to use CMake:

cmake . &&
make &&
make install

You may use cmake -LH or tools such as cmake-gui or ccmake to examine the available configuration options.

Alternative build systems

Alternatively, you may use any other build system. You will need to:

• Prepare your avs_commons_config.h file. See the comments in avs_commons_config.h.in for details.
• Configure your build system so that:
  • At least all *.c and *.h files from src and include_public directories are preserved, with the directory structure intact.
  • All *.c files inside src or any of its direct or indirect subdirectories are compiled.
  • src and include_public directories are included in the header search path when compiling avs_commons.
  • include_public directory or a copy of it is included in the header search path when compiling dependent application code.

An example simplistic build process for a Unix-like shell could be:

# configuration
cp include_public/avsystem/commons/avs_commons_config.h.in include_public/avsystem/commons/avs_commons_config.h
vi include_public/avsystem/commons/avs_commons_config.h  # manually configure the library here

# compilation
cc -Iinclude_public -Isrc -c $(find src -name '*.c')
ar rcs libavs_commons.a *.o

# installation
cp libavs_commons.a /usr/local/lib/
cp -r include_public/avsystem /usr/local/include/

Contact, contributing

• Your feedback is important! Feel free to create an Issue here on GitHub.
• If you would like to contribute to avs_commons just send us a pull request.